A Vermont man who pleaded guilty to kidnapping and killing his niece — and producing child pornography — is looking at a life sentence plus 70 years in prison.

In 2013, Michael Jacques of Randolph, then 47, pleaded guilty in federal court to a charge of kidnapping with death resulting for the 2008 abduction, sexual assault and killing of his 12-year-old niece, Brooke Bennett of Brookfield.

In exchange for pleading guilty, Jacques was spared a possible death sentence. However, in a sentencing memorandum filed Friday in federal court, U.S. Attorney Tristram Coffin is looking for a sentence that would ensure Jacques never goes free.

“For that unspeakable crime this Court should sentence Jacques to life imprisonment without the possibility of parole, and should impose a consecutive 70 years imprisonment for his production of child pornography involving a different young girl,” he wrote.

Jacques has a history of sexually assaulting girls that dates back more than 30 years, Coffin said. In 1985, a pregnant 15-year-old who was seeking an abortion told police she was carrying Jacques’ child, and said he had been assaulting her since she was 10 or 11 years old.

Jacques, who was 18 at the time, was arraigned on a charge of sexual assault but that charge was later dismissed, “reportedly after the Jacques family pressured the victim,” the memorandum states.

Court records state that in 1987, Jacques sexually assaulted a 13-year-old girl at his Barre apartment after plying her with alcohol. However, after interviewing the victim, prosecutors offered him a plea agreement in which Jacques received a three-year deferred sentence.

The conviction was expunged from his record. In 2013, the victim died of a drug overdose.

In 1993, Jacques was convicted for kidnapping and sexually assaulting an 18-year-old Rutland High School student. This time, Jacques received a six-to-20-year sentence.

He was placed on probation in 1996. In 2000, he requested and was granted release from ongoing sex offender treatment.

Coffin wrote that Jacques said at the time, “I have slowly evolved from a selfish, self involved, cruel, manipulative, hurting young man into a man, while still (possessing) a degree of all those characteristics, I can, for the first time in my life, be proud of.”

In 2006, Jacques was released from probation for his 1993 sexual assault conviction.

The 61-page memorandum outlines in horrific detail years of abuse of both Bennett and the other girl with whom he produced the pornography, as well as “Breckenridge,” a fictional group created by Jacques that scared the girls into compliance.

The memorandum discusses several online aliases Jacques created.These included“Charles,” who threatened the girls and their families, and “Eric,” who sent Bennett a romantic poem that she framed and hung on her bedroom wall.

After killing Bennett June 25, 2008, Jacques fabricated an online trail of emails and messages to deflect attention from himself, prosecutors said. Investigators later recovered a number of videotapes that showed his assault of the other girl, the memorandum states.

“Nearly six years after Jacques kidnapped and murdered Brooke, a mother, father, sister, brother, grandmother and countless other relatives and friends grieve her loss,” Coffin wrote.

“No sentence can undo Jacques’ crimes,” Coffin continued, “but on May 20 this Court should banish Jacques — pedophile, a psychopath, a monster, the embodiment of evil who preyed on girl after girl after girl for more than two decades — from civil society to imprisonment for the remainder of his life.”

Jacques is scheduled to be sentenced Tuesday in federal court in Burlington.